This is a study of the social, psychological, and cultural correlates of drug use of Mexican-American youth. Of the three major Hispanic groups in the United States, Mexican-Americans are the largest and the fastest growing. In coming years, projections show that Mexican-Americans will emerge as a major economic, political, and social force. They will soon make up more than half of the western population. The well-being of the west and of the nation could depend heavily on the strength and contribution of this group. Drug use could sap this strength. Half of Mexican- Americans are under 22, and since drug use almost always starts in adolescence, a very large part of the population are still at risk. There are other factors that also suggest high risk, including economic problems, prejudice, and most of all, problems in education. Mexican-American youth have very high rates of school dropout. Some factors, such as strong religious and family values, could also work against drug use, and could be assets that could be used in prevention and treatment. The first step in planning prevention and intervention programs for Mexican- American youth, however, is determining what characteristics are associated with drug use and how they are interrelated. This study will establish the correlational links between social and psychological characteristics and drug use in Mexican-American youth, and determine whether there are differences in these links between Mexican-American youth and Anglo youth living in the same communities. Gender differences and age differences will also be examined. The drug use correlates include measures to assess cultural identification, family socioeconomic status, intactness of family, family relationships, family sanctions, religious identification, school adjustment, self-confidence, feelings of being socially accepted, shyness, depression, anxiety, anger, belief in drug dangers, tolerance of deviance, deviant behaviors, and peer drug associations. Implications for prevention, treatment, and future research will be considered.